Add a MovePicker c'tor specialized for qsearch

This simple patch shows a speed increase of
more then 2% !

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/movepick.cpp

@@ -18,11 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
-////
-//// Includes
-////
-
 #include <cassert>
 
 #include "history.h"
@@ -31,11 +26,6 @@
 #include "search.h"
 #include "value.h"
 
-
-////
-//// Local definitions
-////
-
 namespace {
 
   enum MovegenPhase {
@@ -58,11 +48,6 @@ namespace {
 }
 
 
-////
-//// Functions
-////
-
-
 /// Constructor for the MovePicker class. Apart from the position for which
 /// it is asked to pick legal moves, MovePicker also wants some information
 /// to help it to return the presumably good moves first, to decide which
@@ -77,21 +62,22 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
   badCaptureThreshold = 0;
   badCaptures = moves + MOVES_MAX;
 
+  assert(d > DEPTH_ZERO);
+
   pinned = p.pinned_pieces(pos.side_to_move());
 
-  if (ss && !p.is_check())
+  if (p.is_check())
+  {
+      ttMoves[1].move = killers[0].move = killers[1].move = MOVE_NONE;
+      phasePtr = EvasionsPhaseTable;
+  }
+  else
   {
       ttMoves[1].move = (ss->mateKiller == ttm) ? MOVE_NONE : ss->mateKiller;
       searchTT |= ttMoves[1].move;
       killers[0].move = ss->killers[0];
       killers[1].move = ss->killers[1];
-  } else
-      ttMoves[1].move = killers[0].move = killers[1].move = MOVE_NONE;
 
-  if (p.is_check())
-      phasePtr = EvasionsPhaseTable;
-  else if (d > DEPTH_ZERO)
-  {
       // Consider sligtly negative captures as good if at low
       // depth and far from beta.
       if (ss && ss->eval < beta - PawnValueMidgame && d < 3 * ONE_PLY)
@@ -99,6 +85,23 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
 
       phasePtr = MainSearchPhaseTable;
   }
+
+  phasePtr += int(!searchTT) - 1;
+  go_next_phase();
+}
+
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h)
+                      : pos(p), H(h) {
+  int searchTT = ttm;
+  ttMoves[0].move = ttm;
+  ttMoves[1].move = MOVE_NONE;
+
+  assert(d <= DEPTH_ZERO);
+
+  pinned = p.pinned_pieces(pos.side_to_move());
+
+  if (p.is_check())
+      phasePtr = EvasionsPhaseTable;
   else if (d >= DEPTH_QS_CHECKS)
       phasePtr = QsearchWithChecksPhaseTable;
   else
@@ -354,4 +357,3 @@ Move MovePicker::get_next_move() {
       go_next_phase();
   }
 }
-

src/movepick.h

@@ -17,23 +17,13 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
 #if !defined MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
-////
-//// Includes
-////
-
 #include "depth.h"
 #include "history.h"
 #include "position.h"
 
-
-////
-//// Types
-////
-
 struct SearchStack;
 
 /// MovePicker is a class which is used to pick one legal move at a time from
@@ -49,7 +39,8 @@ class MovePicker {
   MovePicker& operator=(const MovePicker&); // silence a warning under MSVC
 
 public:
-  MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL, Value beta = -VALUE_INFINITE);
+  MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value beta);
+  MovePicker(const Position& p, Move ttm, Depth d, const History& h);
   Move get_next_move();
   int number_of_evasions() const;
 
@@ -70,10 +61,6 @@ private:
 };
 
 
-////
-//// Inline functions
-////
-
 /// MovePicker::number_of_evasions() simply returns the number of moves in
 /// evasions phase. It is intended to be used in positions where the side to
 /// move is in check, for detecting checkmates or situations where there is